Process of napping and saturating felt



F. W. ADAMS.

PROCESS OF NAPPING AND SATURATING FELT AND PRODUCT THEREOF.

APPLICATION FILED JUNE 29. 191B.

'1 ,3 1 L862. I Patented July 29, 1919.

INVENTOR ATTORNEY UNITED STATES PATENT OFFICE.

FLOYD W. ADA HIS, 0F HUDSON HEIGHTS, NEW JERSEY, ASSIGNOR TO BARRETT COMPANY, A. CORPORATION OF NEW JERSEY.

PROCESS OF NAPIING AND SATURATING FELT, AND PRODUCT THEREOF.

Specification of Letters Patent. Patented July 29, 1919.

Application filed June 29, 1918. Serial No. 242,611.

To all 'whomit may concern:

Be it known that I, FLOYD W. ADAMS, a citizen of the United States, residing at Hudson Heights, in the county of Bergen and State of New Jersey, have invented cer' tain new and useful Improvements in Processes of Napping and saturating Felt, and Product Thereof, of which the following is a specification.

This invention relates to a new and useful construction materialand the method of producing the same. It is directed more partlcularly to the saturation of felts or paper whlch are to be used as building materials, and is designed to enable a more thorough saturation or impregnation of the felt or paper base than has been possible with the usual methods of saturation.

In practising this invention I may take an ordinary sheet of felt or paper such as is used for making roofing material, etc. and nap or pick the surface thereof either at the felt-making mill or just prior to saturating It in order to produce a surface which will more readily absorb a saturant. The felt or paper having the napped surface on one or both sides may be immersed in a liquid bath of the usual saturating or waterproofing materials such as tar, oil, or any suitable waterproofing materials already in use for such purposes. The interior of the felt or paper which is unaffected by the nappingprocess will absorb the customary amount of saturant during the saturating operation, but the napped surface, bein more loose or less compact, will mechanica ly carry a correspondingly larger amount of the saturant, a portion of which will be adually absorbed by the denser interior the felt or pa or with the lapse of time after the sheet lias passed through the saturating bath.

The invention will be understood by .reference to the accompanying drawing in which the figures represent somewhat diagrammatical a sheet being napped and passed through a bath of saturating material.

In this drawing the reference character 1 represents a roll of felt or paper which has been produced in the ordinary way as, for example, on a paper-ma'kin machine having a foraminous cylinder. n making this sheet the usual aper-making stock, such as rag or wood fi ers, may be used. After the sheet has been made and dried in the customary manner it is rolled up into the of them, as indicated at 3' may be 'driven' in the opposite direction by any suitable means, not shown. It is obvious that the number and disposition of these cylinders may be varied to suit the circumstances so that only one or both sides of the sheet will be napped and-the degree and depth of the napping may be varied within wide limits. The particular sort of napping device is immaterial, the desideratum being that the surface or surfaces of the sheet should be napped to some depth so that the outside fibers will be loosened up to a considerable extent and thereby become more porous and absorbent for the saturant.

After the surface of the sheet 2 has been napped as indicated at 5, the napped sheet may be passed through a liquid bath 6 of waterproofing material such as oil, tar, creosote, asphalt, etc. If necessary, this bath may be heated in any convenient or suitable manner to render the saturant more fluid.

As the sheet 2 asses through the saturant 6 the interior of the same which has been unaffected by the napping operation absorbs a certain amount of saturant, while the outside napped portion, being loose and less dense, mechanically carries a proportionately larger amount of the saturant. This excess may be regarded as a layer or layers 7 of saturant on the outside of the sheet, having the fibers, which constitute the napping, inters ersed therethrough and being revented rom dripping off by means of t ese fibers. The saturated sheet m y then be rolled up into the roll 8 where a portion of the layer 7 of saturant is gradually absorbed into the more dense portions of the sheet. In this way a larger amount of saturant canbe introduced into a sheet of felt than has been hitherto possible with the usual 'saturatin processes. If desired the sheet may be rol ed up while the saturant is still warm or the roll may be kept heated by outside heating agencies in order to promote the absorptlon whenever found necessary.

The napping of sheets makes them me-.

chanically weaker, but the'increase in the amount of saturation which is obtainable by napping serves to increase the strength thereby rendering them, after saturation, approximately as strong as the saturated unnapped sheet. Tests have shown that with some saturants, such as asphalt, the saturated napped sheets stronger than the unnapped saturated sheets.

The grade of a saturated sheet is partially determined by its weight, so that an increaseof the saturant serves to increase its value,

and improve its waterproofing qualities.-

After the sheets have been saturated, they maybe used for the same purposes heretofore available for the usual saturated sheets.

, A useful and salable product may, how ever, be produced merely by napping the 3. The process of producing a construc tion material which comprises the steps of napping the,surfaoe of a building felt and applying waterproofing material to the napped felt.

4. The process of producing a construction material which comprises the steps of were actually napping the surface of a building felt and applying waterproofing material to the I napped felt and rolling the treated sheet up so that the Waterproofing material in the napped portion is partially absorbed into the interior. I

. 5. The process which comprises saturating the surface of a napped sheet of paper making material with waterproofing material and subsequently causing the saturant to penetrate the interior of the sheet.

6. The process of saturating a sheet of napped felt which comprises the steps of introducing saturant into the interior of the felt, applying a layer of excess saturant to the surface of the sheet and subsequently causing the excess saturant to become absorbed into the interior.

7 The process of producing a construction material which comprises treating the surface of a sheet-of paper-making material so as to render said surface I nore porous than the interior of said sheet and saturating said sheet with waterproofing material.

8. The process of producing a construction material which comprises picking the surface of a sheet of-paper-making material so as to render said surface more readily absorbent of waterproofing material, and saturating said sheet with waterproofing material. c

9. As an article of manufacture, a sheet of felt having its surface treated so that the capacity of said surface for absorbing waterproofing material is proportionately greater than the interior of said sheet, said sheet being saturated wlth waterproofing material. In testimony whereof I aflix my signature.

FLOYD w. ADAMS. 

